Benzo/Naphthodifuranone‐Based Polymers: Effect of Perpendicular‐Extended Main Chain π‐Conjugation on Organic Field‐Effect Transistor Performances

Abstract

For polymer semiconductors, the backbone structure plays an essential role in determining their physicochemical properties and charge transport behaviors. In this work, two donor–acceptor‐type polymers (P‐BDF and P‐NDF) based on benzodifuranone (BDF) and naphthodifunarone (NDF) as electron‐deficient moieties and indaceno‐dithiophene as electron‐rich groups are designed, synthesized and, for the first time, applied in organic field‐effect transistor. P‐BDF and P‐NDF differ from their backbone structures while P‐BDF has a more planar backbone conformation due to its smaller conjugated core size and P‐NDF features a perpendicular‐extended main chain structure. As a result, P‐BDF polymer exhibits bathochromic optical absorption, deeper molecular orbital energy levels, and more importantly, closer π‐stacking and stronger aggregation in the solid state and thus affords a more promising hole mobility of up to 0.85 cm2 V−1 s−1 in OFET devices, while that of the P‐NDF‐based devices is only 0.55 cm2 V−1 s−1. The results suggest the great potential of BDF/NDF‐type chromophores in constructing novel organic semiconductors and also indicate that the main chain coplanarity of polymer semiconductors is more essential than the sole extension of π‐conjugations (especially at the perpendicular direction of polymer main chains) for the design of high‐performance OFET materials.

Flexible Organic Photovoltaics with Star‐Shaped Nonfullerene Acceptors End Capped with Indene Malononitrile and Barbiturate Derivatives

“…[44][45][46][47] On the other hand, coplanarity may easily induce J-type aggregation. [48,49] A significant aggregation in the solid state can negatively influence the performance of these NFAs in photovoltaics (see Section 2.4), as expected based on earlier reports. [50,51] The films of TPA-T-INCN, TPA-2T-INCN, and TPA-2T-BAB blends with P3HT exhibit a wide absorption between 350 and 650 nm (Figure 2d).…”

Conjugated Conductive Polymer Materials and its Applications: A Mini-Review

“…Recently, Deng et al (2018) introduced S and F atoms to adjust the polymer backbone and obtained a polymer with hole mobility up to 0.65 cm 2 V −1 s −1 . Zhang et al then reported that the main chain coplanarity of polymer semiconductors is more essential than the sole extension of π-conjugation (especially perpendicularly to polymer main chains) after investigating two benzo/naphtodifuranone-based polymers ( Figure 1G ) ( Li et al, 2021 ). The same group also found that substituting the oxygen atoms for sulfur atoms in the diketopyrrolopyrrole core could not only improve the charge transfer mobility, but also convert p-type materials into ambipolar type semiconductors ( Figure 1H ) ( Zhang et al, 2018c ; Zhang et al, 2019a ).…”

Sulfonated Dopant‐Free Hole‐Transport Material Promotes Interfacial Charge Transfer Dynamics for Highly Stable Perovskite Solar Cells

“…In a TAS molecule, the well‐matched D‐D‐D (donor‐donor‐donor) alignment provides a highly planar molecular backbone and extended π‐conjugation, which favor the efficient hole transfer within the individual molecule as well as between the adjacent molecules. [ 18 ] In addition, the sulfur atom contained in the functional group can modify the perovskite surface via dipole intermolecular interaction between a lone pair and Pb 2+ , when TAS is used as a dopant‐free HTM in n‐i‐p PSCs. Based on our theoretical and experimental results, TAS exhibits remarkably enhanced hole extraction, hole transport, and device performance compared to TAO and DAS.…”